they post updates of things they are making (music, games, and comics mostly); and they share photos that they've taken, and links and comments to news that they find interesting. Compared to Lemmy, it's more personal, because when you respond you are talking directly to a person that you are likely to talk to again.

You can do all that same stuff on Lemmy/reddit, except the comments are actually organized and readable. Trying to read a continuous comment thread on Twitter is such a pain.